Composite material



Patented July 5, 193a 2.123.155 l a a comrosrrn MATERIAL I Frazier Grofl,

mesne assignments,

Charleston, W. Va., assignor, by

to Union Carbide and Carhon Corporation; a corporation of New York Nb Drawing. Application July 15. 1931,

a Serial No. 551,061,

6 Claims. (cl. 154-43) ticles, or stock from which to make ,finished articles, by combining a plurality of types of resinous materials, whereby one ofthe resinous can be caused to supply qualitiesin which .another, is deficient, all as moreparticularly hereinafterdescribed. j i

, ad Thermo-setting resins, for example phenolmethylene, phenol-aldehyde, phenol-iurfural, 1O

urea-formaldehyde and glyptalresins, can be formed ,at moderatetemperatures, but higher temperatures render them permanently immobile and infusible. f Suchresins are extensively used 3 1 as molding plasticsland possess desirable propmechanical strength and q ins also possess certain from their ,usefulness.

erties,,such as insolubility, resistance, to heat,

rigidity; buttliese resqualities which detract these resins are "diiiicult to prepare in light colors or their colors tend to be unstable toward light; others are characterized by a low degree of electrical arc/resistance; and those prepared ,iromphenols usually retain a phenolic odor.

but the heatresistance of the vinyl resins is usually inferior to, that oi the thermo-setting resins. Y l

Thus, it is, immediately apparent that if the desirable qualities .of each type of resin could .be combined in a composite material, the latter would be superior for many purposes to any product which would be made from either type of resin alone. But on attempting to mold the two types of resins together to form a composite, combining a surface of vinyl resin with a core or base of an lnfuslble ,thermo-setting resin, the unexpected fact was discovered that vinyl resins molded against cured or iniusible thermo-setting resins do not adhere thereto. In fact this lack of adhesion is so marked that vinyl resins may be molded in matrices formed from thermo-setting resins, which have been converted to the infusible state, in lieu of metal molds. Also, difficulties are encountered in molding vinyl resins against thermo-setting resins which are not cured but which are in the potentially reactive state, for the reason that the temperature The invention relatesto the production of armaterials For example, some of and time required to cause the theme-setting resins to be converted to the final iniusible state differ widely from a the optimum conditions for molding vinyl resins.

'lhe present invention avoids or minimizes these difllculties and has. for its principal object the provision of a process for forming cornposlte vinyl resins. l

,I havefound by experimentationthat an object comp osed of infusible and non-absorbing thermo-setting resin can be provided with integral absorbent surface portion to which a vinyl resin will adhere when it is molded thereagainst. This discovery has'enabled me to attain the objectof the inventionand to prepare composite articles by molding each resin under conditions best suited to its properties. The resultant composite combines the desirable properties of both materials. a

The following examples are illustrative of the invention:

,I. A plurality of sheets of paper were impregnated with potentially reactive phenolic plastic and placed together between unimpregnated sheets so that the latter formed the top and bottom layers of the assembly. The assembly was then molded ata temperature of about 150 C. to 170 C. until the thermo-setting resin was entirely converted to the infusible state. The re: sulting productwas a laminated press board having an infusible interior, integrally joined to absorbingsurfaces of untreated paper. This press board was then dipped in a solution of vinylresin in acetone, the solvent was evaporated, and the board was molded at about 130 to 140 to form a composite material having an infusible thermo-setting resin. interior with asurface of vinyl resin. The vinyl resin solution may be colored with lakes, dyes or pigments.

If a thicker surface of vinyl resin is desired, the resin may be applied in the formof preformed sheet, or as powder. This can be done with or without the application of a solution of vinyl resin to the original press board. Instead of using materials including thermo-setting resins and sheets of paper which are impregnated with the thermosetting resin, untreated paper may be used and the thermosetting resin may be distributed between the layers of paper.

II. A piece of a fibrous material, such as pulp board, was treated with a solution of a potentially reactive phenolic resin. The solvent was evaporated and theboard ,wasbaked until the thermo-setting resin was partially converted to the infusible state. Sheets of paper treated on '2partsofrosinltotparts'of e e y The impregnated .rnaterial wasjdried "and baked both, as described in Example I.

The pulp board which is impregnated with a, partially cured phenolic resin may be molded directly against a vinyl resin composition without the inclusion of the absorbing layers of paper.

This is possible because the. uncured phenolic r 1 in is at least partially soluble inth'ecvinylresin,

and because the temperature at whichthe vinyl resin is molded, viz., about 130C; is sufficient to phenolic resin to complete the conversion of the the infusible final state. t i a, mix u e o P en c re we n cbninositmn and afviriyi resin molding eoniposif qeic t i m s t fb ith no i es composition and" so p sor the vin l res n com? position was dusted oy er pape'r impregnated with a potentially reactive phenolicresini This assem: bly was in turn covered with vlnyl resin sheet stock or molding compositionand molded at 150? C. to form a phenolicresin composite surfaced with a vinyl resimcomposltlon. "I

Y iii... A piece of felt wasimpreg'nated with a solution of to curefthe phenolic resin ,Thistreatment pro! du'ced an'impregnated basej which was soft and. which; remained. fibrous, but which was sitifier and stronger than; thejo'riginal material The phenolic resin was'dilutedwith the rosin. hence,

it "waspossible to create a bond between the; im -f.

pregnated base and a Vin l resin. A vinyl resin molding composition" wasthen molded against the upper and lower surfaces of the impregnated metef' elmte mair lr smsmee j w i e- This typejorproces be advantageously ap-- plied to the formationof articles having a; softer interior with a hard exterlor'of a; vinyl'resin' come position. M i e V. A molding composition including both thenmo-sttingand vinyl' resins was prepared as follows; aquantity of wood flour was treated with a solution containing, the reaction. product of 2 mols of formaldehyde and l mol. of urea. This mixturef'was driedand baked in an. oven at 90"v to 100C. to cure theresi'n. Three hundred parts of this product was mixed with 250 parts of vinyl resin,.l part of. carnauba wax and. 1. part of cal clum stearate. The mixture wasrolled for about phenolicrefsin andfrqiln containingabout and insoluble 'in' water.

agent; such as carnauba wax, in conjunction with wthe stabilizer is also advantageous.

, incorporationtherewith of rosinfl '7 five minutes on heated differential rolls to thoroughly incorporate the ingredients. The product after being rolled was ground and used as a general molding composition.

Many types of vinyl resins may be used to form 5 my new material. A preferred vinyl resin is a product resulting from the polymerization of a mixture of 70% to 95%v of vinyl, chloride and 5% to;30% of vinyl'acetate, and which is less than 30% soluble in cold (20 to 30 C.) toluene. I

prefer to insure complete stability of the vinyl resin by incorporating therewith a basic stabilizing substance which does not include any acidforming or oxidizinggroups in its composition,

such asalkeline eartii metal salts of the fatty l5 acids or natural 'orQartificial acid resins, such stabilizers preferably being colloidal in nature The use of a fluxing Many modifications of my process and material are'possible" and are included within the invern tion as defined bythe appended claims.

I',claim 1 5" '1. 1i compositematerial comprising an infusibl'e thermo-settihg resin firmly united to a'vinyl res-" in through an intermediate bonding surface com' prising a thermo-setting resin modified by the incorporation therewith of another resinous material to-which said vinyl resin is'adherent.

2. A com'pos'ite material comprising aninfusible thermo s'etting' resin firmly united to a vinyl resin: through an intermediate bonding surface comprising a thermo-setting' resin modified by the I v 3: composite material comprising n infusible thermo-setting resin firmly unitedto "a vinyl resin through an intermediate'bonding surface com prising a thermo-setting resin modified by the incorporation" therewith of a vinyl resin. 40

J 4'.ffA coinpos'ite material comprisingan infusible' phenolic resin portionflrmly united to'a. surface portioiijfcfjviriyl resin through an intermediate bondinggflayer comprising about equal parts of; phenolic resina'nd another resinous material to which said vinyl resin is adherent.

5 A composite material comprising an infusible phenolic resin'portion firmly unlted to a surface portion of vinyl resin through an"intermediate bonding layerjcomprising about equal parts of phenolic resin and rosin.

6. A compositematerial comprising an infusible phenolic resin portion flrmlyvu'nited toa surface portion ofvinyl resin through an intermediate bonding layer comprising about e'cjual partsof phenolic resin and a vinyl resin.

" FRAZIERHGRFGFF. 

